Axles have long been used for wheeled vehicles, in which the axle being placed cross wise of a longitudinal axis and carrying on its outer ends wheels attached through hubs to the axle on which the vehicle is rolled. Generally a front axle is used for guiding the motor vehicle. The front axles are generally used solely for guiding but sometimes also for propelling. A rear axle generally is a driving axle, but in the instance of a front wheel drive axle, the rear axle provides for rear wheels that follow the driving wheels of the front axle. Front axles use conventional steering assemblies in which road wheels are mounted on steering-pivots or knuckles carried on the outer end of the axle. Other types of steering may be used, for example slow-moving vehicles such as farm tractors, road rollers and traction engines.
The hub rotatingly mounts to the end of the axle. The hub is either driven, such as rear wheel drive axles, or dead (i.e., non-driven, but rotatingly following the driven wheels.) The connection of the hub to the axle is protected by a seal. The seal defines a cavity which typically is filled with oil or grease to provide a barrier to entry of contaminants and to provide lubrication of the moving parts during operation of the motor vehicle.
While sealed axle/hubs have been used successfully, severe operating conditions may lead to seal failure. Upon failure of the seal, the lubricating material leaks from the seal. The leakage creates openings for entry of destructive debris. Equipment used in severe conditions such as mining, earth moving, construction, farming, and the like often include water and dirt mixtures. Clay, shell rock, and gravel create dust, dirt and grit. Water, dirt, sulfurous materials and the like entering the seal causes damage to the rotating parts. Low places in mines typically are filled with gravel. Pools of water stand in passageways of mines. The axles get coated with the mixture which dries and becomes a crust. The watery mixture also may enter the seals into the axle. The mixture wears out bearings. Persons engaged in operating heavy duty equipment industry in severe environments have sought to prevent hub seals from leaking.
Accordingly, there is a need in the art for an improved axle/hub seal. It is to such that the present invention is directed.